The present invention relates to arrangements for treating fibers in general, and more particularly to arrangements for texturizing continuous filament threads by means of a heated flowing medium.
There are already known various constructions of texturizing arrangements of the above type. So, for instance, the Swiss patent specification No. 527 931 discloses an arrangement for texturizing continuous filament threads by means of a heated flowing medium, which arrangement is equipped with a so-called crimping portion which includes a stuffing chamber and in which the threads are longitudinally compressed to produce crimping of the threads. The crimping portion is provided with openings through which the medium that is fed into the stuffing chamber with the threads can escape from the stuffing chamber. In this known arrangement, the crimping portion is formed by lamellae which are arranged in a star-shaped configuration. The lamellae are fixedly mounted with a narrow side facing into the stuffing chamber for the thread. These lamellae are securely held at both of their ends by respective rings and, in this manner, they are held at predetermined spacings, so that the medium which is required for the performance of the texturizing operation can escape between the lamellae. Another texturizing arrangement of this type is described and illustrated in the Swiss patent application No. 2656/84-6.
Experience gained during the use of the texturizing arrangements or nozzles of the above type has shown that the retardation and attendant accumulation of the continuous filament thread in the stuffing chamber of the crimping portion of the texturizing arrangement, which is needed for imparting the crimp to the filament thread, cannot be accomplished under all circumstances, especially at the commencement of the operation of the texturizing arrangement, without employing some auxiliary means or measures. The result is that the continuous filament threads leave the texturizing arrangement uncrimped.
In order to avoid this result and to assist the formation of the crimp in the continuous filament thread at the commencement of the operation of the texturizing arrangement, it has been proposed and attempted to close the exit opening of the texturizing arrangement, that is, the opening through which the continuous filament thread leaves the interior of the texturizing arrangement, for a short period of time so as to provide for the initial retardation of the continuous filament threads in the stuffing chamber. However, it has been established that this procedure has a serious drawback, in that it is very difficult to determine the correct period of time for closing the exit opening of the texturizing arrangement. If the actual period of time for which the exit opening is closed is too short, proper retardation of the threads is not achieved. On the other hand, if the actual period of time for which the exit opening is closed is too long, the stuffing chamber can become blocked by the thread accumulating therein.
Another way which has been proposed for assisting this retardation effect involved blowing an air stream into the stuffing chamber in a direction substantially opposite to the direction of advancement of the continuous filament threads through the interior of the texturizing arrangement. In addition to disadvantages which are akin to those discussed above, such a method also has the drawback that the continuous filament threads can become lodged between the lamellae, and this can lead to undesirable disturbances and operation interruptions.